Specimen #1 Polytrichum commune, Moss
Name: Polytrichum commune
Common Name: Common Haircap Moss
Family: Polytrichaceae
Collection Date: September 15, 2016
Habitat: Shady area, surrounded by trees, both alive and dead, growing in soil.
Location: Nelson Ledges
Description: Short growing moss, with small pointed leaves. Leaves are notched around in a circle, with no particular order, and contain microscopic, spike like appendages. Overall coloring is deep purple/brown, with little green. No sexual characteristics were found on this sample.
Figure 1: Polytrichum commune sample.
Figure 2: Singular leaf. The leaf was characterized as being a lance-type. The dark portion in the center is a large midrib. Outside of each leaf, there are several thorn like structures that can be seen under a microscope.
Figure 3: The leaf, currently from the position that is attached to the stem. The midrib beings small and thin, and quickly increases the farther it moves up the leaf. The edge of the sample shows the clasping base.
Key Used: McKnight, K. B. (2013). Common mosses of the Northeast and Appalachians. Princeton, NJ: Princeton University Press.
Keying Steps:
Growth-Acrocarp- Lance
1b. Plants darker green, yellow green, or brownish black,
shoots loosely associated or if densely packed the not in domed mounds; leaves
flat or folded but not tubular, with midrib usually visible at least at base of
leaf……….3
3b. Plants on soil, rocks, trees, or logs in dry areas, or if in wetter areas, not submerged in water; leaves not folded at base...4
4b. Leaf surface not rippled or wavy when wet...9
9a. Leaves mostly > 4mm long (some at base or tip of stem may be shorter)...10
10b. Wet leaves stiff, thick, and opaque when held up to light(reminiscent of conifer needles); midrib difficult to see except at leaf base...14
14b. Leaf margin toothed except along clasping leaf base; capsules with or without disk...17
17b. Capsules 4-sided like a box....19
19a. Capsules with a disk at attachment to stalk.....Polytrichum commune
3b. Plants on soil, rocks, trees, or logs in dry areas, or if in wetter areas, not submerged in water; leaves not folded at base...4
4b. Leaf surface not rippled or wavy when wet...9
9a. Leaves mostly > 4mm long (some at base or tip of stem may be shorter)...10
10b. Wet leaves stiff, thick, and opaque when held up to light(reminiscent of conifer needles); midrib difficult to see except at leaf base...14
14b. Leaf margin toothed except along clasping leaf base; capsules with or without disk...17
17b. Capsules 4-sided like a box....19
19a. Capsules with a disk at attachment to stalk.....Polytrichum commune
I think this one needs to be looked at again. Those teeth on the leaf are a distinctive characteristic that is not being used in the key as it likely should be and is not characteristic of Andreae rothii. The microscope pictures are very nice though and will help. Is it possible to get a brighter, more magnified picture of the intact sample?
ReplyDeleteYes! I like this ID much better.
ReplyDelete